The Cylons are the adversaries of the humans who inhabit the Twelve Colonies. Their destruction of the Colonies forms the central plotline of the Battlestar Galactica sagas.
- See Cylons (RDM) for more about the robotic and humanoid Cylons in the Re-imagined Series.
- See Cylons (TOS) for more on the reptilian and robotic Cylons of the Cylon Empire in the Original Series.
- See Cylons (SDS) for more on the Cylons of the failed DeSanto/Singer continuation of Battlestar Galactica.